The present invention generally pertains to a conference calling arrangement for a digital switching network and more particularly to an arrangement for capturing data of a time shared conference circuit for examining the data for error or verification conditions.
Historically, switching systems were equipped with a number of conference circuits. When a request for a conference call is detected by such a switching system, this system would select an unused conference circuit to connect each of the conferees in a conference call arrangement. In this scheme, one conference call would require one conference circuit.
With the advent of time division switching systems, conference circuits are required to manipulate PCM voice samples in an associated time slot switching environment. Time division switching systems utilize common equipment for a number of subscribers. One conference circuit for each conference call is inefficient. Since a time shared conference circuit handles a large amount of conference calls, it is required that for a fault the data and time slot of the fault be preserved.
One such conference circuit for manipulating PCM voice samples is taught by U.S. Pat. No. 4,126,766, issued on Nov. 21, 1978, and having the same successor in interest as the assignee of the present application. This conference circuit is a three-port device for use in a private automatic branch exchange. This conference circuit handles only a single conference call at a time. Each conference call requires a separate conference circuit. No provision is made for obtaining data and time slot information for detection of a fault. Threshold level detection and last speaker retention features are provided by this circuit. In addition, all three conferees' voice samples are compared before outputting the resultant loudest speakers' samples.
Another digital multiport conference circuit is taught by U.S. Pat. No. 4,175,215, issued on Nov. 20, 1979, and having the same successor in interest as the assignee of the present application. This circuit provides for handling a single conference call at a time. Again, no provision is made for obtaining data and time slot information from the voice data stream for a fault detection. In addition, threshold level detection and last speaker retention features are provided.
Another multiport conference circuit is taught by U.S. Pat. No. 4,274,155, issued on June 16, 1981, and having the same successor in interest as the assignee of the present application. Similar to the above mentioned circuits, this circuit also handles one conference call at a time and provides no data and time slot information for fault detection.
Each of the above mentioned circuits suffers from the same deficiency of not providing data and time slot information for a fault detection in a time shared conference circuit.
Accordingly, it is the object of the present invention to provide for obtaining data and time slot information for fault or normal conditions in a time shared conference circuit.